Method of fabricating well heads



Jan. 17, 1956 c. WALKER METHOD OF FABRIGATING WELL HEADS Filed Nov. 16, 1951 FIG. 1

INVENTOR. D. C. WALKE ATTORNEY United States Patent "ice 2,130,799 METHOD or FABRICATING WELL HEADS David C. Walker, Tulsa, Okla., assignor to Walker Well Heads Inc., Tnlsa, 0kla., a corporation of Oklahoma Application November 16, 1951, Serial No 256,781

2 Claims. (Cl. 29-480) This invention relates to improvements in well heads for oil and gas wells and the like, and more particularly, but not by way of limitation, to an improved well head body and a method of fabricating the same.

As it is well known, the well head bodies utilized on oil and gas wells comprise a large coupling of a size to connect directly with the well casing and two smaller couplings secured to diametrically opposite sides of the larger coupling. These wellhead bodies areusually either forged or cast as an integral unit. It will be apparent that the casting or forging of an article of such configuration is a delicate and time consuming operation. Furthermore, both the large and small couplings must be provided with internal threads after the casting or forging operation, which entails various threading machine setups and changes, as well as a considerable length of machine time. The cost of these wellhead bodies is, therefore, unnecessarily increased. Heretofore it has been impractical to fabricate the well head bodies from standard size couplings because of the distortion of the threads during and subsequent to the welding of the smaller couplings onto the large coupling.

The present invention contemplates a novel well head body fabricated from standard size couplings. Apertures are formed in the walls of a large coupling and then the outer surface of the larger couplingis machined around each aperture in such a manner to receive smaller couplings prior to the welding of the couplings. Also, a tapered plug, is wedged into the large coupling prior to the welding operation. In this manner, the internal threads of the large coupling are precluded from distorting upon cooling of the metal subsequent to the welding operations. Thus, the small couplings may be efficiently welded to the large coupling and the threads of the large coupling will retain their original size and configuration.

The resulting well head body may be manufactured and distributed at a very material saving as compared to a forged or cast well head body.

An important object of this invention is to provide a well head body which may be economically manufactured.

Another object of this invention is to provide a novel method of fabricating a well head body from standard sized couplings.

A further object of this invention is to provide a novel method of fabricating a well head body from standard sized couplings wherein the internal threads of the couplings will not be distorted during the fabricating operations.

A still further object of this invention is to provide a well head body having standard threads for simple and convenient connection with various conduits at the surface of a well, and having a long service life.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

1 2,730,799 Patented Jan. 17, 1956 In the drawings: 1 t

Figure 1 is an elevational view of a novel well head having a quarter section removed to expose the internal structure thereof.

Figure 2 is an elevational view of the well head body illustrating the machined surfaces of the large well head body coupling.

Figure 3 is a partial sectional view taken along lines 3--3 of Fig. 2 with a portion of the well head body shown in plan.

Referring to the drawings in detail, and particularly Fig. 1, reference character 2 generally indicates a well head having a novel body portion generally indicated at 4. The well head body 4 comprises a large standard sized coupling 6 of a size to connect directly with the well casing (not shown). Two smaller standard sized couplings 8 are connected to diametrically opposite sides of the larger coupling 6 to form the completed well head body. a

In fabricating the body 4, radially extending apertures 10 are first formed in diametrically opposite sides of the larger coupling 6 substantially in the central portion of the coupling. The outer surface of the coupling 6 around each of the apertures 10 is then machined or cut away as illustrated in Figs. 2 andfl. The areas 12 and 14 directly above and below each aperture 10 are cut away in such a manner to completely receive the upper and lower portions of therespective coupling 8. In machining the areas 12 and 14 to fiat surfaces, shoulders 13 and 15 are formed which overlie the outer surface of the respective coupling 8 when the body 4 is assembled as shown in Fig. 1. Additional machine surfaces or fly cuts 16 are provided on each side of each aperture 10 to interconnect the areas 12 and 14. The areas 16 are machined to a flat surface to receive a portion of the inner end 18 of the respective coupling 8. It will beapparentz that the width of the machined areas or surfaces 16 is limited by the wall thickness of the larger coupling 6, since the areas 12, 14 and 16 should be in the same vertical plane. In actual practice, the width of each area 16 is approximately one-third as large as the width of the areas 12 and 14.

After the machining operation, the ends 18 of the couplings 8 are placed in abutting relationship with the respective areas 12, 14 and 16 and are then welded, as illustrated in Fig. 1. The couplings 8 are preferably formed from one standard sized coupling by merely cutting the standard sized coupling in half. The inner ends 18 of each coupling 8 should be flat in order to make good contact with the machined areas 12, 14 and 1.6, and are preferably machined in order to make a proper contact. Prior to the welding operations, a rigid tapered plug (not shown), preferably formed out of steel, is wedged into the upper end 20 of the large coupling 6. The tapered plug is preferably formed on the same taper as the threads 22 in the upper portion of the large coupling 6 in order to contact the crest of each thread and prevent contraction of the threads. The threads 22 are machined with a taper amounting to approximately three-quarter inch to one foot. This is normal in compliance with API specifications. Furthermore, the threads 22 may be slightly rounded if desired at the ends thereof in order to facilitate the removal of the conforming tapered plug. The tapered threads 24 in the lower portion of the coupling 6, which connect with the well casing, are not appreciably affected by the welding operation, therefore, no plug is required in the lower portion of the coupling.

During the welding operation, the metal of both the couplings 8 and the coupling 6 will obviously expand by the inherent application of the heat. After the welding operation, the metal of both the couplings 8 and the couplings 6 will obviously contract. However, the metal of the coupling 6,in-proxiii1ity with the apertures 10,

contracts to a 'greaterdegree than 'the'diameters of "the couplings 8. Thus, the shoulders 13 and 15in efiect shrink upon the end 18 of the respectiye cgupling 8 to as is weli st me al nre isl as ri d wnne i It rptgttg rt at the ta e s plu (11m. hown) prevents un tie contraction, and therefore distortion, of the threads-32. lathe wun ing .fitand. par isu ar adi it thearsttnms 9,- The sourlinss 8 do no exna or contra'ct to such an extent to damage the threadsZG ther np il fh T3 rnei tt rece e u ab t n 9 1 (not shownj and facilitate the assembly of the bushing 2.8 i thewc thea best 4- er surfacelitt of the bushing 28 is tay and inwardly to receive a plurality of pered ,downw vided and they are preferably interconnectedby a suitable locking ring 512, serrations or teeth 44 are pro:

Yl filuQ theimie lsvtfa of each s member w' he outer surface of the well tubing 46. It will 9 3. a be app ent that upon downward movement of the slips '40, the taper ed s urfaces as force the slips-40 inwardly intq qvt t w th he t LA Pee s-2t? .q l m m s!! pr v dea se betwe n h bushing Zti'faqqthd W t nin 4,6- ui b metallic in 50, usu ll e le fiuri i rin s- Pro ide b v and below the pack-0&5 to facilitate'compression of the pack-off 48 t e usua trn A a e r pa n nut 52 s. ite ledl awed lat e u e r o n 2 to proyi deiadownwargd force on the junk rings and pack-off 318. Iransverse aperture 54 may be provided in the upper 'endof packing nut 52 to facilitate rotation 9t he; 2 15; frde irer- From the foregoing, it is apparent that the present invsat qn m i em sim le n u e well e b which may be economicallymanufactured. The I present inve ntionalso pi des a novfel method of fabricating a wel head body frorn standard sized couplings in such a manner that fill? of; body will not be distorted,

he bushing 28 and has a plurality ring 48, disposed above the and the side couplings will .be rigidly connected to the larger coupling;

Changes may be made infthe combination and arrangement of parts as heretofore set forth in the specifications and shown in the drawings, it-being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims without departing from the spirit of the invention.

I claim:

l. A method of fabricating a well head body from a large and two smaller internally threaded couplings, comprising the steps of forming two diametrically opposed radially extending apertures inthe wall of the large coupling, fly cuttingthe apertures to .provide fiat machined areas on the outer surface thereof, Wedging a tapered plug in the large coupling against the crests of the threads therein, welding one end of each of the smaller couplings to each, of said ,flat rnachinedareas of the outer surface of th large, oupl ng imme iat ly-adj ce t eab rtu e t a d, eta n e plu i h ai rsou li g su seq ent to the welding operation to. precludesub stantial dis: iv 9 t e e s int h la e oupli 2. A methodof fabrieating, a well head body from. a

' largeand small internally threaded couplings comprisr ing the steps ofv forminga radially extendingaperture in one wall of the large coupling, machining .the outer sur face of'the large coupling aroundthevaperture to provide a flat surface of a size corresponding to the. cross sectional size of the smaller coupling with outwardly extending shoulders above and belowthe ilatsur face wedging a aper pl the a e cou n ag inst e. cr s s of the threads therein, placing one ,end of the; smaller cou-. pling incontact-withfthe' fiat surface and the adjacent a e f he tw rd :ex cnslit ssh u ders e d n the smaller coupling to the largercoupling to the said mach le s if c an reta ning hep us. in; h r e w F in u s nt 1 m eld n opera io t p clu edi tortion of the threads in the large coupling.

RfifQiflEfiS Cited in. th le f his w UNITED STATES l PATEN TS Kershaw Feb. 5, 1935" 

